Power-operated compressor



ERX'IAN AND C. W. FREES.

POWER OPLRATED COMPRESSOR.

armcaixox man mm 21,1920.

. ACK

Patented Nov. 8, 1921.

IHVENTORS FRANK ACKERMA/Y C HAPLES W FR5 BY 2 z I, ATTORNEY5 UNITED STATES PATENT OFFICE.

FRANK ACKERMAN AND CHARLES W. FREES, OF ST. LOUIS, MISSOURI, ASSIGNOR TO CURTIS & CO. MFG. 00., OF WELLSTON, MISSOURI, A CORPORATION OF MISSOURI.

POWER-OPERATED COMPRESSOR.

Specification of Letters Patent.

Patented Nov. 8, 1921.

To (ZZZ whom it may concern:-

Be itknown that we, FRANK ACKERMAN and CHARLES W. Ferns, citizens of the United States, residing in the city of St.

ouis, and county of St. Louis, Missouri, respectively, have invented a certain new and useful Improvement in Power- Operated Compressors, of which the following is a full, clear and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to power-operated compressors or pumps of the kind wherein means is provided for holding one or more active valves of the compressor or pump unseated when the apparatus is set in operation so as to relieve the load on the driving means.

In apparatus of the type above referred to it is the common practice to use a speed governor or similar device to hold a valve of the compressor or pump open when the driving means is first started and thereafter permit said valve to seat and function properly after the driving means has attained a certain predetermined speed.

Due to the fact that the-controlling means for the valve of the compressor consists of a speed governor or device that is rendered operative only when a certain predetermined speed of the driving means it attained, such a controlling means is not satisfactory for all classes of work. For example, where a small compressor is directly connected to an alternating current electric motor of, say, 1 to 5 H. P., the motor, when started, attains its full speed very quickly, thus making it impracticable to use an unloading device comprisin a speed governor on account of the fact t at such a device would require too delicate an adjustment for commercial purposes.

The object of our invention is to provide a power-operated compressor or pump that is equipped with an unloading device or easy starting device which is so constructed that one or more active valves of the compressor or pump will be maintained in an inoperative condition for a certain length of time after the driving means is set in operation, and thereafter will seat and function properly, regardless of the speed at which the driving means is then operating.

The figure of the drawings is a side elevational view, partly in vertical section, of a power-operated air compressor equipped with an unloading device or easy starting deviceconstructed in accordance with our invention.

Referring to the drawings, A designates a compressor which may be an air compressor, pump or other similar machine that is adapted to be driven by an electric motor or other suitable driving means (not shown), that is operatively connected with the compressor, as, for example, by means of a belt (not shown) that passes over a pulley 1 formed by the fly wheel of the compressor.

of a means for causing one of the valves of the compressor to remain unseated for a certain period of time after the apparatus has been set in operation, irrespective of the speed of the compressor or of the driving means that actuates the compressor. a In the form of our invention herein shown said means consists of an actuating device 2 associated with one of the valves 3 of the compressor, mechanism for causing said actuating device 2 to start to move in a direction to seat the valve 3 or permit said valve to seat when the driving means of the apparatus is set in operation and a dash pot or other suitable means B that retards the movement of said -valve actuating device 2 so as to prevent the valve 3 fromseating for a certain length of time after the apparatus has been started.

hen the apparatus ceases operating, the device 2 unseats the valve 3 and maintains it in an inoperative condition. Various means can be used for operating the valve actuating device 2, but we prefer to use a lever 4 which is moved in one direction by a spring 5 and in the opposite direction by a collar 6 that is operatively connected with centrifugal devices C mounted on the fly wheel 1 of the compressor and so arranged that the collar 6 will hold thezlever 4 and the valve actuating device 2 in the position shown in the drawing when the apparatus is at rest. When the motor or driving means of the apparatus is started, the centrifugal devices C operate practically instantly to cause the collar 6 to move to the right, thus permitting the spring 5 to expand and move the lever 4 in a direction to shift the valve actuating device 2 to the left. Said va'lve actuating device is provided with plunger an irregularly shaped slot 2", comprising" a horizontal portion and an inclined portion, that receives a pin 7* on a plunger 7 whose lower end bears against valve 3, one end of said valve actuating device 2 being pivotally connected to the plunger 9 of the dash pot B. The opposite end of said valve actuating device 2 is pivotally connected to the upper end of the lever 4, and the spring 5 that actuates said lever is arranged below the fulcrum of the lever so as to normally exert pressure on samein a direction tending to move the valve actuating device 2 into a position to cause or permit the valve 3 to seat under the influence of the spring 3 of said valve. When the apparatus is set in operation the centrifugal devices C move outwardly practically instantly and the valve actuating device 2 starts to move to the left, due, of course, to the pressure which the spring 5 exerts on the lever 4 as soon as the collar 6 moves to the right or away from the lower end of the lever 4. Although the device 2 starts to move to the left or into a position to permit or cause the valve 3 to become seated, as soon as the driving means of the apparatus is setin operation, the plunger 9 of the dash pot B checks or retards the movement of said device 2 so as to prevent the valve 3 from seating until after the apparatus has been in operation for a certam length of time. The valve 3 remains unseated until the inclined portion of the slot 2 in the actuating device 2 reaches such a point that it will engage the pin 7 on the 7 and move said plunger upwardly, thus permitting'the spring 3 of the valve 3 to seat said valve 3 or move it into its closed position. When the apparatus is stopped the centrifugal devices-C move inwardly or toward the center of the fly wheel of the compressor, move the lever 4 in such a direction that the valve actuating device 2 is shifted to the right, thereby causing the horizontal portion of the slot 2 in said device 2 to engage the pin 7 of the plunger 7 and depress said plunger so as to unseat the valve 3. In the form of our invention herein illustrated the cylinder of the dash pot B is mounted on an extension 10 on the head of the compressor and is provided with a guideway in which the plunger 7 slides vertically in alinement with the stem 8 of the valve 3. The lever 4 is arranged vertically at one side of the cylinder of the compressor and is pivotally mounted on a bracket 11 on the top portion of the crank case of the compressor. We wish it to be understood, how

ever, that the details of construction of the device are immaterial, so far as our broad idea is concerned, and further, that while we have herein illustrated our invention embodied in an apparatus provided with s the stem 8 of the.

and thus cause the collar 6 tocentrifugal mechanism that controls the position of a spring actuated element whose movement in one direction is retarded by a dash pot, that our invention,-broadly stated, consists of a power operated compressor or pump equipped with means for holding one or more valves of the compressor or pump unseated or inoperative for a certain length of time after the driving means of the apparatus has been-started and which permits or causes said valve or valves to seat or become operative at the expiration of said time, irrespective of the speed at which the driving means of the apparatus is then op crating.

Having thus described our invention,what we :claim as new and desire to secure by Letters Patent, is:

1. A power-operated compressor or pump provided with an unloading device or easy starting device comprising a mechanically operated mechanism which prevents one of the cylinder valves of the compressor from functioning properly during the starting of the apparatus, a variable speed deyice combined with the driving element of the apparatus and a means cooperating with said device for causing said mechanism to start to operate to restore the cylinder valve of the compressor to its normal operative {condition when the apparatus is started, and means for retarding the action of said mechanism so as to insure the compressor remaining inactive for a certain period of time after the apparatus has been set in operation, irrespective of the speed of the driving element.

2. A power-operated pump or compressor, comprising a valve, an actuating device for said valve, a spring for moving said device in one direction, means for retarding the movement of said device when it is moving under the influence of said spring, and means that operates upon the stopping of the apparatus to move said device in the opposite direction and place said spring un er tension.

3. A power operated pump comprising a valve, vice for said valve, a spring for moving said device in one direction, a centrifugal mechanism which moves said device 1n opposition to said sprin when the apparatus is stopped and WhlCh permits said device to move. under the influence of the spring when the apparatus is started, and means for retarding the movement of said device when it is moving under the influence of said spring for the purpose described.

4. A power operated compressor or pump, comprising a mechanically operated ,member that holds one of the valves of the compressor unseated and which starts to move in a direction to effect the seat-- ing of said valve when the apparatus 18 set inoperation, and a dash pot or similar means for checking the movement of said member for the purpose described.

5. A power operated compressor or pump, comprising a valve, a valve actuating device, a lever for operating said device, a dash pot or similar means combined with said device so as to retard the movement of same in one direction, a spring for moving said lever in one direction, and a centrifugal mechanism for moving said lever in the opposite direction.

6. A power operated compressor or pump, comprising a cylinder provided with a valve, a mechanical mechanism for unseating said valve and permitting said valve to seat, means whereby the starting of the apparatus causes said mechanism to start instantly to move in a direction to permit the valve to seat or become operative, and means for retarding the movement of said mechanism in the direction just referred to so as to hold the valve unseated for a certain length of time after the apparatus has valve, a plunger arranged to act on said,

valve, a valve actuating device provided with an irregular slot that receives a pin on said plunger, a lever connected to one end of said device, a dash pot whose piston is connected to the opposite end of said device, a spring for moving said lever in one direction, and a centrifugal mechanism built into the fly wheel of the compressor for moving said lever in the opposite direction.

FRANK ACKERMAN. CHARLES W. FREES. 

